A class that defines the rounding precision to be used when formatting numbers in NumberFormatter. More...

#include <numberformatter.h>

Inheritance diagram for icu::number::Precision:

Static Public Member Functions
static Precision	unlimited ()
	Show all available digits to full precision. More...

static FractionPrecision	integer ()
	Show numbers rounded if necessary to the nearest integer. More...

static FractionPrecision	fixedFraction (int32_t minMaxFractionPlaces)
	Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator). More...

static FractionPrecision	minFraction (int32_t minFractionPlaces)
	Always show at least a certain number of fraction places after the decimal separator, padding with zeros if necessary. More...

static FractionPrecision	maxFraction (int32_t maxFractionPlaces)
	Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator). More...

static FractionPrecision	minMaxFraction (int32_t minFractionPlaces, int32_t maxFractionPlaces)
	Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator); in addition, always show at least a certain number of places after the decimal separator, padding with zeros if necessary. More...

static SignificantDigitsPrecision	fixedSignificantDigits (int32_t minMaxSignificantDigits)
	Show numbers rounded if necessary to a certain number of significant digits or significant figures. More...

static SignificantDigitsPrecision	minSignificantDigits (int32_t minSignificantDigits)
	Always show at least a certain number of significant digits/figures, padding with zeros if necessary. More...

static SignificantDigitsPrecision	maxSignificantDigits (int32_t maxSignificantDigits)
	Show numbers rounded if necessary to a certain number of significant digits/figures. More...

static SignificantDigitsPrecision	minMaxSignificantDigits (int32_t minSignificantDigits, int32_t maxSignificantDigits)
	Show numbers rounded if necessary to a certain number of significant digits/figures; in addition, always show at least a certain number of significant digits, padding with zeros if necessary. More...

static IncrementPrecision	increment (double roundingIncrement)
	Show numbers rounded if necessary to the closest multiple of a certain rounding increment. More...

static CurrencyPrecision	currency (UCurrencyUsage currencyUsage)
	Show numbers rounded and padded according to the rules for the currency unit. More...

Friends
struct	impl::MacroProps

struct	impl::MicroProps

class	impl::NumberFormatterImpl

class	impl::NumberPropertyMapper

class	impl::RoundingImpl

class	FractionPrecision

class	CurrencyPrecision

class	IncrementPrecision

class	impl::GeneratorHelpers

Detailed Description

A class that defines the rounding precision to be used when formatting numbers in NumberFormatter.

To create a Precision, use one of the factory methods.

Draft:: This API may be changed in the future versions and was introduced in ICU 60

Definition at line 457 of file numberformatter.h.

Member Function Documentation

◆ currency()

static CurrencyPrecision icu::number::Precision::currency ( UCurrencyUsage currencyUsage )

static

Show numbers rounded and padded according to the rules for the currency unit.

The most common rounding precision settings for currencies include Precision::fixedFraction(2), Precision::integer(), and Precision::increment(0.05) for cash transactions ("nickel rounding").

The exact rounding details will be resolved at runtime based on the currency unit specified in the NumberFormatter chain. To round according to the rules for one currency while displaying the symbol for another currency, the withCurrency() method can be called on the return value of this method.

Parameters

currencyUsage Either STANDARD (for digital transactions) or CASH (for transactions where the rounding increment may be limited by the available denominations of cash or coins).

Returns: A CurrencyPrecision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 60

◆ fixedFraction()

static FractionPrecision icu::number::Precision::fixedFraction ( int32_t minMaxFractionPlaces )

static

Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator).

Additionally, pad with zeros to ensure that this number of places are always shown.

Example output with minMaxFractionPlaces = 3:

87,650.000
8,765.000
876.500
87.650
8.765
0.876
0.088
0.009
0.000 (zero)

This method is equivalent to minMaxFraction with both arguments equal.

Parameters

minMaxFractionPlaces The minimum and maximum number of numerals to display after the decimal separator (rounding if too long or padding with zeros if too short).

Returns: A FractionPrecision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 60

◆ fixedSignificantDigits()

static SignificantDigitsPrecision icu::number::Precision::fixedSignificantDigits ( int32_t minMaxSignificantDigits )

static

Show numbers rounded if necessary to a certain number of significant digits or significant figures.

Additionally, pad with zeros to ensure that this number of significant digits/figures are always shown.

This method is equivalent to minMaxSignificantDigits with both arguments equal.

Parameters

minMaxSignificantDigits The minimum and maximum number of significant digits to display (rounding if too long or padding with zeros if too short).

Returns: A precision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 62

◆ increment()

static IncrementPrecision icu::number::Precision::increment ( double roundingIncrement )

static

Show numbers rounded if necessary to the closest multiple of a certain rounding increment.

For example, if the rounding increment is 0.5, then round 1.2 to 1 and round 1.3 to 1.5.

In order to ensure that numbers are padded to the appropriate number of fraction places, call withMinFraction() on the return value of this method. For example, to round to the nearest 0.5 and always display 2 numerals after the decimal separator (to display 1.2 as "1.00" and 1.3 as "1.50"), you can run:

Precision::increment(0.5).withMinFraction(2)

Parameters

roundingIncrement The increment to which to round numbers.

Returns: A precision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 60

◆ integer()

static FractionPrecision icu::number::Precision::integer ( )

static

Show numbers rounded if necessary to the nearest integer.

Returns: A FractionPrecision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 60

◆ maxFraction()

static FractionPrecision icu::number::Precision::maxFraction ( int32_t maxFractionPlaces )

static

Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator).

Unlike the other fraction rounding strategies, this strategy does not pad zeros to the end of the number.

Parameters

maxFractionPlaces The maximum number of numerals to display after the decimal mark (rounding if necessary).

Returns: A FractionPrecision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 60

◆ maxSignificantDigits()

static SignificantDigitsPrecision icu::number::Precision::maxSignificantDigits ( int32_t maxSignificantDigits )

static

Show numbers rounded if necessary to a certain number of significant digits/figures.

Parameters

maxSignificantDigits The maximum number of significant digits to display (rounding if too long).

Returns: A precision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 62

◆ minFraction()

static FractionPrecision icu::number::Precision::minFraction ( int32_t minFractionPlaces )

static

Always show at least a certain number of fraction places after the decimal separator, padding with zeros if necessary.

Do not perform rounding (display numbers to their full precision).

NOTE: If you are formatting doubles, see the performance note in unlimited.

Parameters

minFractionPlaces The minimum number of numerals to display after the decimal separator (padding with zeros if necessary).

Returns: A FractionPrecision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 60

◆ minMaxFraction()

static FractionPrecision icu::number::Precision::minMaxFraction	(	int32_t	minFractionPlaces,
		int32_t	maxFractionPlaces
	)

static

Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator); in addition, always show at least a certain number of places after the decimal separator, padding with zeros if necessary.

Parameters

minFractionPlaces	The minimum number of numerals to display after the decimal separator (padding with zeros if necessary).
maxFractionPlaces	The maximum number of numerals to display after the decimal separator (rounding if necessary).

Returns: A FractionPrecision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 60

◆ minMaxSignificantDigits()

static SignificantDigitsPrecision icu::number::Precision::minMaxSignificantDigits	(	int32_t	minSignificantDigits,
		int32_t	maxSignificantDigits
	)

static

Show numbers rounded if necessary to a certain number of significant digits/figures; in addition, always show at least a certain number of significant digits, padding with zeros if necessary.

Parameters

minSignificantDigits	The minimum number of significant digits to display (padding with zeros if necessary).
maxSignificantDigits	The maximum number of significant digits to display (rounding if necessary).

Returns: A precision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 62

◆ minSignificantDigits()

static SignificantDigitsPrecision icu::number::Precision::minSignificantDigits ( int32_t minSignificantDigits )

static

Always show at least a certain number of significant digits/figures, padding with zeros if necessary.

Do not perform rounding (display numbers to their full precision).

NOTE: If you are formatting doubles, see the performance note in unlimited.

Parameters

minSignificantDigits The minimum number of significant digits to display (padding with zeros if too short).

Returns: A precision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 62

◆ unlimited()

static Precision icu::number::Precision::unlimited ( )

static

Show all available digits to full precision.

NOTE: When formatting a double, this method, along with minFraction and minSignificantDigits, will trigger complex algorithm similar to Dragon4 to determine the low-order digits and the number of digits to display based on the value of the double. If the number of fraction places or significant digits can be bounded, consider using maxFraction or maxSignificantDigits instead to maximize performance. For more information, read the following blog post.

http://www.serpentine.com/blog/2011/06/29/here-be-dragons-advances-in-problems-you-didnt-even-know-you-had/

Returns: A Precision for chaining or passing to the NumberFormatter precision() setter.

Draft:: This API may be changed in the future versions and was introduced in ICU 60

The documentation for this class was generated from the following file:

numberformatter.h

Static Public Member Functions

Friends

Detailed Description

Member Function Documentation

◆ currency()

◆ fixedFraction()

◆ fixedSignificantDigits()

◆ increment()

◆ integer()

◆ maxFraction()

◆ maxSignificantDigits()

◆ minFraction()

◆ minMaxFraction()

◆ minMaxSignificantDigits()

◆ minSignificantDigits()

◆ unlimited()